Essays on Public Health Insurance

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Essays on Public Health Insurance

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Title: Essays on Public Health Insurance
Author: Wettstein, Gal
Citation: Wettstein, Gal. 2016. Essays on Public Health Insurance. Doctoral dissertation, Harvard University, Graduate School of Arts & Sciences.
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Abstract: Over the last ten years there have been dramatic changes in the health insurance environment in the United States, spurred on by broad reforms in the public health insurance sector. In 2006 the Medicare Prescription Drug, Improvement and Modernization Act went into effect, providing broad access to prescription drug insurance for millions of elderly Americans. In 2014 the main provisions of the Patient Protection and Affordable Care Act began to be felt, dramatically changing health insurance markets, particularly for those seeking non-group coverage. These legislative changes both raise questions regarding how well the policy changes meet their goals, as well as offering new variation with the potential to answer questions of fundamental economic significance.

This dissertation addresses such important questions surrounding the effectiveness of public health insurance in meeting policymakers’ goals, and the implications of public health insurance for private markets. In the three chapters of this dissertation I utilize the policy changes of Medicare Part D and the Affordable Care Act to provide quasi-experimental estimates of retirement lock, of the correlation of risk aversion and crowd-out of private insurance, and of the effectiveness of the individual health insurance mandate in expanding coverage.

The first part studies the implications of public drug insurance for labor markets. This part examines whether the lack of an individual market for prescription drug insurance causes individuals to delay retirement. I exploit the quasi-experiment of the introduction of Medicare Part D, which provided subsidized prescription drug insurance to all Americans over age 65 beginning in 2006. Using a differences-in-differences design, I compare the labor outcomes of individuals turning 65 just after 2006 to those turning 65 just before 2006 in order to estimate the causal effect of eligibility for Part D on labor supply. I find that individuals at age 65 who would have otherwise lost their employer-sponsored drug insurance upon retirement decreased their rate of full-time work by 8.4 percentage points due to Part D, in contrast to individuals with retiree drug insurance even after age 65 for whom no significant change was observed. This reduction was composed of an increase of 5.9 percentage points in part-time work and 2.5 percentage points in complete retirement. I use these estimates to quantify the extent of the distortion due to drug insurance being tied to employment, and the welfare gains from the subsidy correcting that distortion. The results suggest that individuals value $1 of drug insurance subsidy as much as $3 of Social Security wealth.

The second part of this dissertation considers the effect of public drug insurance on private drug coverage, with a focus on the correlation of crowd-out and risk aversion. I utilize Health and Retirement Survey data around the time of introduction of the Medicare Part D prescription drug insurance for the elderly in order to estimate crowd-out of private prescription drug insurance. I use individuals between the ages of 55 and 64, who are not eligible for the program, as a control group relative to individuals aged 65 to 75, who are eligible. I take a differences-in-differences approach to estimation by comparing outcomes before and after 2006, when Medicare Part D went into effect. I construct measures of risk aversion by exploiting unique questions eliciting risk preferences in the Health and Retirement Survey, as well as information on whether individuals have other kinds of insurance, or engage in risky behaviors. I find substantial differential crowd-out by risk aversion: every standard deviation increase in risk aversion was associated with about 5 percentage points less crowd-out, over a base crowd-out rate of 50%-60%. More risk averse individuals also saw greater reductions in out-of-pocket spending on prescription drugs due to Part D, particularly at high levels of spending: at the 85th percentile of spending an individual one standard deviation more risk averse than the average experienced a decline of $110/year due to Part D eligibility, above and beyond the gains for an averagely risk averse individual of $382/year.

The third part of the dissertation estimates the effectiveness of the individual mandate in the Patient Protection and Affordable Care Act in expanding health insurance coverage. This paper studies the impact of the individual health insurance mandate in the Patient Protection and Affordable Care Act (PPACA) on health insurance coverage. This mandate went into effect in 2014, alongside various other elements of the PPACA. I focus on individuals ages 26-64 who are ineligible for the subsidies or Medicaid expansions included in the PPACA to isolate the effect of the mandate from these other components. To account for changes unrelated to the PPACA that occur over time and affect insurance coverage I utilize a control group of residents of Massachusetts who were already subject to mandated insurance following the 2006 health care reform in their state. Employing a differences-in-differences design applied to data from the American Community Survey, I find that the mandate caused an increase of 0.85 percentage points in health insurance coverage, or a 17% decline in the uninsurance rate. This increase was concentrated in coverage purchased directly by individuals, rather than acquired through an employer, and predominantly affected younger individuals. Both these observations are consistent with the mandate ameliorating adverse selection in the individual health insurance market.
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